rs1555769166

Positions:

• chr19-7639772-CTG-C

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_006949.4(STXBP2):​c.212_213del​(p.Leu71ArgfsTer46) variant causes a frameshift change. The variant allele was found at a frequency of 0.00000479 in 1,461,500 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: STXBP2 NM_006949.4 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 6.35

Genes affected

STXBP2 (HGNC:11445): (syntaxin binding protein 2) This gene encodes a member of the STXBP/unc-18/SEC1 family. The encoded protein is involved in intracellular trafficking, control of SNARE (soluble NSF attachment protein receptor) complex assembly, and the release of cytotoxic granules by natural killer cells. Mutations in this gene are associated with familial hemophagocytic lymphohistiocytosis. Alternatively spliced transcript variants encoding different isoforms have been noted for this gene. [provided by RefSeq, Jan 2013]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 19-7639772-CTG-C is Pathogenic according to our data. Variant chr19-7639772-CTG-C is described in ClinVar as [Pathogenic]. Clinvar id is 538150.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
STXBP2	NM_006949.4	c.212_213del	p.Leu71ArgfsTer46	frameshift_variant	4/19	ENST00000221283.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
STXBP2	ENST00000221283.10	c.212_213del	p.Leu71ArgfsTer46	frameshift_variant	4/19	1	NM_006949.4	P4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1461500 Hom.: 0 AF XY: 0.00000275 AC XY: 2 AN XY: 727026

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000630

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Familial hemophagocytic lymphohistiocytosis 5 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Apr 24, 2019

Loss-of-function variants in STXBP2 are known to be pathogenic (PMID: 19804848, 22451424). This variant has not been reported in the literature in individuals with STXBP2-related disease. ClinVar contains an entry for this variant (Variation ID: 538150). This variant is not present in population databases (ExAC no frequency). This sequence change creates a premature translational stop signal (p.Leu71Argfs*46) in the STXBP2 gene. It is expected to result in an absent or disrupted protein product. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.060		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1555769166; hg19: chr19-7704658;